Method for embossing an absorbent article using a segmented anvil

ABSTRACT

A method for embossing an absorbent article using a segmented anvil and attaching a release paper to a backsheet having depressed regions.

FIELD OF THE INVENTION

The invention relates to a method for embossing an absorbent articleusing a segmented anvil member and the application of an adhesive to theabsorbent article.

BACKGROUND OF THE INVENTION

Rotary embossing systems have traditionally been used to emboss the websthat form absorbent articles. Typical embossing systems have includedrotary embossing rolls and cooperating, rotary anvil rolls. Differentembossment dies can be fixed to rotary embossing rolls to produce avariety of desired embossment regions for absorbent articles.

A typical embossed absorbent article, such as feminine sanitary napkincomprises a topsheet, absorbent core and backsheet, the backsheet isusually attached to the top sheet prior to the embossment of thetopsheet and absorbent core. The attachment of the backsheet to theabsorbent core prior to embossment has limited the depth of theembossment regions, as if the embossment is too deep the backsheet maybe damaged during the embossment process, such as by cutting or tearingthe backsheet. The backsheet is typically made of a water resistantmaterial, such as plastic, which makes the backsheet more vulnerable todamage, than for example a non-woven web. In addition to harming theappearance of the absorbent article, damage to the backsheet cancompromise the effectiveness of the absorbent article, as a damagedbacksheet could allow absorbed fluids to leave the absorbent article andcontact the skin or clothes of a wearer. It has also been difficult toemboss an absorbent article to a uniform depth along the entireembossment region. This is especially true when the embossment regionhas one or more closed ends, for example embossment regions in the shapeof a peanut or oval. The separation distance between the embossing rolland rotary anvil roll increases at the ends of the ends of theembossment regions resulting in less pressure being allied by theembossing dies, and a corresponding reduction in depth in the embossmentregions. The lack of pressure is increased when the ends of theembossment region are closed, as the pressure is spread out along aneven greater surface area.

Deep channel embossments in an absorbent article provide improved fit ofthe absorbent article to the wearer's body, which is important indelivering superior protection performance. Deep channel embossmentsalso provide a pleasant feminine design to the wearer. Further theembossed region also serves as a fluid barrier that prevents fluid fromrunning off to the side of the absorbent article.

In addition, the process of forming deep channel embossments can produceembossment regions, not only in the surface contacted by the rotaryembossing rolls (typically the body facing surface including thetopsheet), but also in the opposing surface (typically the garmentfacing surface). The garment facing surface of the absorbent core is thesurface that will come in contact with the backsheet. The backsheet willoften conform to the embossments present in the garment facing surfaceof the absorbent core, resulting in an uneven surface in the backsheet.The uneven surface of the backsheet causes problems when trying toattach release paper to the surface of the backsheet. Adhesive isusually applied to the release paper first and then the release paper iscontacted with the backsheet, such that the adhesive holds the releasepaper to the backsheet until use. However, as there are valleys presentin the backsheet due to the embossments the adhesive present on therelease paper will bridge these valleys, and consequently the adhesivewill not come into direct contact with the backsheet. The irregularadhesive contact leads to several problems, including poor adhesivetransfer from the release paper to the backsheet allowing adhesive toremain on the release paper or reducing its effectiveness of remainingon the absorbent article and transferring to an undesired surface, suchas a user's panties. Another problem is that when users peels therelease paper off the pads, the adhesive strings (situation similar togum sticking/string to your shoe when you step on gum and lift yourfoot) between the backsheet and release paper. The adhesive could get toa user's finger and snap back to either release paper or backsheet.These are all undesired usage experience for the users. A furthercomplication is that the adhesive not in contact with the backsheet willnot transfer from the release paper making use of the absorbent articlemore difficult, as the release paper can now stick to unwanted surfaces,complicating attachment of the absorbent article. In addition directapplication of an adhesive to the backsheet, will not apply adhesive tothe valleys formed in the backsheet resulting in the same problems withthe release paper.

A method of forming deep channel embossments is needed that preventsdamage to the backsheet of the absorbent article, provides asubstantially consistent depth to an embossment region, and allows forproper adherence of the release paper to the backsheet.

SUMMARY OF THE INVENTION

A method for embossing an absorbent article is provided that comprisesthe steps of providing a topsheet; providing an absorbent core having agarment facing side and a body facing side and positioning the bodyfacing side of the absorbent core on the topsheet; moving the topsheetand absorbent core in a machine direction; operatively contacting thegarment facing side of the absorbent core with a segmented anvil memberand the topsheet with an embossing member of a rotary embossing deviceto form an embossment region in at least a portion of the topsheet andbody facing side of the absorbent core and a depression region in thegarment facing side of the absorbent core; contacting a backsheet withthe garment facing side of the absorbent core having a depressionregion; applying adhesive in a pattern to the backsheet using anon-contact die means; and operatively attaching a release paper to thebacksheet.

A method for embossing an absorbent article is provided that comprisesthe steps of providing a topsheet; providing an absorbent core having agarment facing side and a body facing side and positioning the bodyfacing side of the absorbent core on the topsheet; moving the topsheetand absorbent core in a machine direction; operatively contacting thegarment facing side of the absorbent core with a segmented anvil memberand the topsheet with an embossment member of a rotary embossing deviceto form an embossment region in at least a portion of the topsheet andbody facing side of the absorbent core and a depression region in thegarment facing side of the absorbent core; contacting a backsheet withthe garment facing side of the absorbent core having a depressionregion; applying adhesive in a pattern to the backsheet using anon-contact die means; wherein the application of adhesive comprises thesteps of extruding adhesive from an extrusion outlet; impinging a flowof air from the extrusion outlet at an angle unto the extrudingadhesive; depositing extruded adhesive onto the backsheet; andoperatively attaching a release paper to the backsheet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic side view of an embodiment of the presentinvention for embossing an absorbent core.

FIG. 2 is a top down partial cut-away view of the body facing surface ofa feminine sanitary napkin having an embossment region.

FIG. 3 is a view of a cross-section of the feminine sanitary napkin ofFIG. 2 along the cross-directional line 3-3.

FIG. 4 is a side view of a rotary embossing device that can be used inthe present invention.

FIG. 4A is a perspective view of a segmented anvil member havingsegmented sections.

FIG. 5 is a top view of an embossing member.

FIG. 6 is a view of a cross-section of the embossment member of FIG. 5along the cross-directional line 6-6.

FIG. 7 is an enlarged view of a cross-section through a portion of anembossing member.

FIG. 8 is an enlarged view of a cross-section through a portion of anembossing member.

FIG. 9 is a diagrammatic side view in partial cross-section of anon-contact die means that can be used in the present invention.

FIG. 10 is an exploded view of the non-contact die means shown in FIG.9.

FIG. 11 is a diagrammatic view illustrating use of one embodiment of thepresent invention in an adhesive application to a feminine sanitarynapkin.

FIG. 12 is a front view of a slotted shim that can be used in anon-contact die means.

FIG. 13 is a front view of a slotted shim that can be used in anon-contact die means.

FIG. 14 is a perspective exploded view of a feminine sanitary napkinhaving adhesive thereon and a release paper.

FIG. 15 is a perspective view of a feminine sanitary napkin having anattached release paper.

FIG. 16 is a view of a cross-section of the feminine sanitary napkin ofFIG. 15 along the cross-directional line 16-16.

FIG. 17 is a view of a cross-section of a feminine sanitary napkin.

FIG. 18 is a view of a cross-section of a feminine sanitary napkin.

FIG. 19 is a picture of a feminine sanitary napkin.

FIG. 20 is a series of pictures showing release paper.

FIG. 21 is a diagram showing the assembly of a compression weight.

FIG. 22 is a diagram illustrating the preparation of a sample.

FIG. 23 is a diagram illustrating the preparation of a sample.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing an embossedabsorbent article, such as a feminine sanitary napkin. The methodincludes moving a topsheet and an absorbent core having a body facingsurface and a garment facing surface, in the machine direction, suchthat they are embossed by a rotary embossing device having one or moreembossing members in operative contact with a rotary segmented anvilmember. The embossing members contact the body facing surface of thetopsheet, forming embossment regions in the body facing surface of thetopsheet and absorbent core and forming depression regions correspondingto the embossment regions in the garment facing surface of the absorbentcore. Following embossment a backsheet covers the garment facing surfaceof the absorbent core web. Adhesive is applied to the backsheet using anon-contact method, such as a spray, and a release paper is thencontacted with the adhesive coated surface of the backsheet.

As used herein, the phrase “absorbent article” refers to devices whichabsorb and contain body liquids, and more specifically refers to deviceswhich may be placed against or near the skin to absorb and contain thevarious liquids, such as those discharged from the body. In typical usethe absorbent articles are not intended to be laundered or otherwiserestored or reused after a single use. Examples of absorbent articlesinclude, but are not limited to: personal care absorbent products, suchas: feminine hygiene products, for example feminine sanitary napkins,pantiliners, tampons, interlabial devices and the like; infant diapers;children's training pants; adult incontinence products; as well asabsorbent wipes.

Absorbent articles, and their individual components, such as a liquidpervious topsheet, a substantially liquid impervious backsheet joined tothe topsheet, and an absorbent core positioned and held between thetopsheet and the backsheet, have a body facing surface and a garmentfacing surface. As used herein, “body-facing surface” means that surfaceof the article or component which is intended to be disposed toward orplaced adjacent to the body of the wearer during ordinary use, while the“garment facing surface” is on the opposite side, and is intended to bedisposed to face away from the wearer's body during ordinary use. Thegarment facing surface may be arranged to face toward or placed adjacentto the wearer's undergarments when the absorbent article is worn. Ingeneral the topsheet is operatively permeable to the liquids that areintended to be held or stored by the absorbent article, and thebacksheet may be substantially impermeable or otherwise operativelyimpermeable to the intended liquids. The absorbent article may alsoinclude other components, such as a secondary topsheet, liquid wickinglayers, liquid distribution layers, barrier layers, and the like, aswell as combinations thereof.

With reference to FIGS. 1 and 2, the method of the invention can have amachine-direction 10 which extends longitudinally, and a lateralcross-direction 12 which extends transversely. The machine-direction 10is the direction along which a particular component or material istransported along and through a particular position of the method. Thecross-direction 12 lies generally within the plane of the material beingtransported through the method, and is aligned perpendicular to themachine-direction 10. Accordingly, in the view of the arrangementrepresentatively shown in FIG. 1, the cross-direction 12 extendsperpendicular to the plane of the sheet of the drawing.

With reference to FIGS. 1, 3 and 4, the embossing method for forming anabsorbent article can include positioning an absorbent 22 core on a webmaterial, such as a topsheet 24. Moving the topsheet 24 and absorbentcore 22, either of which may be in the form of a continuous web orindividual components as shown in FIG. 1, along a machine-direction 10at a selected web speed, and in certain embodiments the topsheet 24 andabsorbent core 22 may pass through two or more precalendering rolls 21.Precalendering may be used as the embossing step can require very highforces to achieve a stable bond. By precalendering, some of thiscompression can be done prior to the actual embossing step.Precalendering is not intended to do any permanent deformation of theabsorbent core 22, but rather to partially compress targeted regions ofthe absorbent core 22 prior to embossing. This allows the embossing stepto “complete” the bond in the embossed regions; the remaining areas ofthe absorbent core 22 are allowed to “rebound” from the Precalenderingstep. Following the precalendering rolls 21 (if used) the topsheet 24and absorbent core 22 are operatively contacted with a rotary embossingdevice 30 to form an embossment region 40 in the body facing surface 23and a depression region 41 in the garment facing surface 27 of theabsorbent core 22.

The rotary embossing device 30, as shown in FIG. 4, includes an outerperipheral surface 32 having a lateral cross-direction 12 and acircumferential-direction 42, and an embossing member 34 located on theouter surface 32. As shown in FIG. 1 the embossing method also includesa segmented anvil member 50 which has been configured to cooperate withthe rotary embossing device 30. Additionally, the segmented anvil member50 can be arranged to provide an operative embossing region which can belocated between the rotary embossing device 30 and segmented anvilmember 50. As shown in FIG. 4A the segmented anvil member 50 may includesegmented sections 51. In certain embodiments, as explained in detailbelow, an embossing member 34 may have one or more closed ends as shownin FIG. 5, forming an embossment region 40 having a larger embossment inthe cross-direction at the ends, which can reduce the depth of anembossment region 40. Current designs use an anvil member having auniform diameter and an adjustable rotary embossing device. A segmentedanvil member 50, as shown in FIG. 4A, having segmented sections 51allows the more complex rotary embossing device to be machined at auniform diameter, and moves the “adjustments” or variability to thesimpler anvil member. Each segmented section 51 may have one or moremovable portions 53, which in the embodiment shown in FIG. 4A arepositioned at the end of each segmented section 51. The movable portions53 can be elevated away from the segmented section 51 reducing the gap(between the rotary embossing 30 device and the segmented anvil member50), using one or more elevation devices, such as a shim 55, at the endof the embossment member 34, thereby compensating for the reduction inpressure. In certain embodiments, the elevation device may be positionedbetween a movable portion and the mandrel to which the movable portionis engaged. In certain embodiments the elevation devices, such as ashim, may have a substantially constant thickness, which in certainembodiments may be from about 0.025 mm to about 0.25 mm. In certainembodiments the thickness of an elevated portion may vary. Further,movable portions may be separate elements from the segmented sections,and may be removed or fixed in place using means known in the art, suchas by using nuts and bolts. In certain embodiments a segmented anvilmember may have from 2 to 6 segmented sections, in certain embodiments asegmented anvil member may have from 3 to 9 segmented sections.

In certain embodiments, the absorbent core 22, if in web form, can becut or otherwise divided to provide individual absorbent cores for usein feminine care articles, such as the feminine sanitary napkin shown inFIGS. 2 and 3. The feminine sanitary napkin 80 can have alengthwise-dimension along the longitudinal direction 10, and atransverse-dimension along the laterally extending, cross-direction 12,which correspond respectively to the machine direction 10 and lateralcross-direction 12 described previously.

The absorbent core 22 is embossed before coming into contact with thebacksheet. This allows the absorbent core 22 to be embossed to a greaterdepth in the embossed regions 40, while substantially avoiding undesiredbreaks or fractures of component portions of an absorbent article, suchas a backsheet.

With reference to FIG. 1, the absorbent core 22 can be configured, forexample by being positioned on a belt, to move at a selected speed inthe machine-direction 10 of the method. In certain embodiments the speedcan be from about 2 meters per second (m/s) to about 9 m/s, and incertain embodiments the speed can be from about 5 m/s to about 7 m/s.

FIGS. 2 and 3 show an absorbent article, which in this instance is afeminine sanitary napkin 80 having an absorbent core 22 positionedbetween a body facing surface 23 comprising a topsheet 24 and a garmentfacing surface 27 comprising a liquid impervious backsheet 28 joined tothe topsheet 24, absorbent core 22, or both. The body facing surface 23of the feminine sanitary napkin 80 has an embossment region 40 having adepth “D” as measured from the surrounding area of the body facingsurface 23 to the lowermost portion of the embossment region 40. Incertain embodiments the depth “D” of the embossment region 40 in thebody facing surface 23 may be between about 20% to about 75% of thethickness “T” of the absorbent article, which in this instance is afeminine sanitary napkin, in certain other embodiments the depth “D” ofthe embossment region 40 may be between about 25% to about 50% of thethickness “T” of the absorbent article. The thickness of the absorbentarticle is measured at room temperature and at standard pressure andhumidity. Embossment regions having this depth provide the benefit ofimproved body fit, good fluid barrier as well as aesthetic visualeffects. The garment facing surface 27 of the feminine sanitary napkin80 has a depression region 41 having a depth “D₁” as measured from thesurrounding area of the body facing surface 27 to the lowermost portionof the depression region 41. In certain embodiments the depth “D₁” ofthe depression region 41 in the garment facing surface 27 may be betweenabout 15% to about 75% of the thickness “T” of the absorbent article,which in this instance is a feminine sanitary napkin, in certain otherembodiments the depth “D₁” of the depression region 41 may be betweenabout 25% to about 50% of the thickness “T” of the absorbent article.While the garment facing surface 27 of the feminine sanitary napkin 80is not directly contacted by the rotary embossing device 30, adepression region 41 is produced. While not being limited to theory itis thought that the depression region 41 in the garment facing surface27 is formed from the tensioning of the topsheet, absorbent core andsecondary topsheet (if present). Following embossment and the removal ofthe rotary embossing device and segmented anvil member the recovery ofthe materials forming the topsheet, absorbent core, and secondarytopsheet draws or pulls the materials back up towards the center of theembossment region and body facing surface of the feminine sanitarynapkin.

The feminine sanitary napkin 80 has a longitudinal axis “L” and may alsobe provided with additional features commonly found in feminine sanitarynapkins, such as “wings” or “flaps” as is known in the art or a fluidacquisition layer to promote fluid transport to the absorbent core 22.Further, the topsheet of the absorbent article can have various optionalcharacteristics, as is known in the art, for example the topsheet canhave apertures to aid in fluid acquisition.

In certain embodiments the topsheet may be compliant, soft feeling, andnon-irritating to the wearers skin and hair. Further, the topsheet isliquid pervious, permitting liquids, such as menses or urine, to readilypenetrate through its thickness. A suitable topsheet may be manufacturedfrom a wide range of materials such as woven and nonwoven materials, forexample a nonwoven web of fibers; polymeric materials such as aperturedformed thermoplastic films, apertured plastic films, and hydroformedthermoplastic films; porous foams; reticulated foams; reticulatedthermoplastic films; and thermoplastic scrims. Suitable woven andnonwoven materials can be comprised of: natural fibers, such as wood orcotton fibers; synthetic fibers, such as polymeric fibers—for examplepolyester, polypropylene, or polyethylene fibers; or from a combinationof natural and synthetic fibers. When the topsheet comprises a nonwovenweb, the web may be manufactured by a wide number of known techniques.For example, the web may be spunbonded, carded, wet-laid, melt-blown,hydroentangled, combinations of the above, or the like.

The backsheet is substantially impervious to liquids, such as menses orurine and may be manufactured from a thin plastic film, although otherflexible liquid impervious materials may also be used. The backsheetprevents the exudates absorbed by the absorbent core from wetting auser's bedding or clothes, for example bedsheets, pants, pajamas andundergarments. In certain embodiments, the backsheet can operativelypermit a sufficient passage of air and moisture vapor out of anabsorbent article, particularly out of the absorbent core, whileblocking the passage of bodily liquids. The backsheet may thus comprise:a woven or nonwoven material; polymeric films, such as thermoplasticfilms of polyethylene or polypropylene; or composite materials such as afilm-coated nonwoven material. In one embodiment, the backsheet can be abreathable backsheet such as that described in U.S. Pat. No. 6,623,464(Bewick-Sonntag et al.) issued 23 Sep. 2003.

As shown in FIG. 3 the backsheet 28 and the topsheet 24 are positionedat the garment facing surface 27 and the body facing surface 23,respectively, of the feminine sanitary napkin 80. In certain embodimentsthe absorbent core can be joined with the topsheet, the backsheet, orboth by known attachment means, such as those well known in the art.However, in certain embodiments of the present invention the absorbentcore is unattached to the topsheet, the backsheet, or both.

The absorbent core 22 in FIGS. 2 and 3 is generally disposed between thetopsheet 24 and the backsheet 28. The absorbent core 22 may comprise anyabsorbent material that is generally compressible, conformable,non-irritating to the wearer's skin, and capable of absorbing andretaining liquids such as urine and other certain body exudates, such asmenses. The absorbent core 22 may comprise a wide variety ofliquid-absorbent materials commonly used in feminine care articles andother absorbent articles, such as comminuted wood pulp, which isgenerally referred to as air felt. Examples of other suitable absorbentmaterials include creped cellulose wadding; melt blown polymers,including co-form; chemically stiffened, modified or cross-linkedcellulosic fibers; tissue, including tissue wraps and tissue laminates;absorbent foams such as foams formed from High Internal Phase Emulsions(HIPEs); absorbent sponges; superabsorbent polymers; absorbent gellingmaterials; or any other known absorbent material or combinations ofmaterials. The absorbent core may further comprise minor amounts(typically less than 10%) of non-liquid absorbent materials, such asadhesives, waxes, oils and the like. Examples of absorbent structuresthat may be used in the present invention are found in U.S. Pat. No.4,834,735 (Alemany et al.) issued 30 May 1989; U.S. Pat. No. 5,625,222(DesMarais et al.) 22 Jul. 1997.

The absorbent core may also include one or more superabsorbentmaterials. Superabsorbent materials suitable for use in the presentinvention are known to those skilled in the art, and may be in anyoperative form, such as particulate form. The superabsorbent materialcan be a water-swellable, generally water-insoluble, hydrogel-formingpolymeric absorbent material, which is capable of absorbing at leastabout 20, in certain embodiments about 30, and in additional embodimentsabout 60 times or more its weight in physiological saline (for example0.9 wt % NaCl). The hydrogel-forming polymeric absorbent material may beformed from organic hydrogel-forming polymeric material, which mayinclude natural material such as agar, pectin, and guar gum; modifiednatural materials such as carboxymethyl cellulose, carboxyethylcellulose, and hydroxypropyl cellulose; and synthetic hydrogel-formingpolymers. Synthetic hydrogel-forming polymers include, for example,alkali metal salts of polyacrylic acid, polyacrylamides, polyvinylalcohol, ethylene maleic anhydride copolymers, polyvinyl ethers,polyvinyl morpholinone, polymers and copolymers of vinyl sulfonic acid,polyacrylates, polyacrylamides, polyvinyl pyridine, and the like. Othersuitable hydrogel-forming polymers include hydrolyzed acrylonitrilegrafted starch, acrylic acid grafted starch, and isobutylene maleicanhydride copolymers and mixtures thereof The hydrogel-forming polymersare preferably lightly crosslinked to render the material substantiallywater insoluble. Crosslinking may, for example, be by irradiation orcovalent, ionic, Van der Waals, or hydrogen bonding. Suitable materialsare available from various commercial vendors, such as the Dow ChemicalCompany and Stockhausen, Inc. The superabsorbent material may beincluded in an appointed storage or retention portion of the absorbentarticle, and may optionally be employed in other components or portionsof the absorbent article.

As shown in FIG. 1, the rotary embossing device 30 can be positionedcooperatively adjacent a segmented anvil member 50. The segmented anvilmember 50 is oriented to counter-rotate relative to the rotary embossingdevice 30.

The rotary embossing 30 device can have a selected roll radius 35. Incertain embodiments the roll radius can be from about 7 cm to about 25cm. In certain other embodiments the roll radius can be from about 11 cmto about 19 cm.

Any conventional power mechanism or system can be employed to drive therotary embossing device 30. Such power mechanisms can include engines,motors, electro-magnetic power systems, fluidic power systems, or thelike, as well as combinations thereof The selected drive system can beconfigured to provide the rotary embossing device 30 with a selectedsurface speed at the outer peripheral rim surface 32, and certainembodiments, the peripheral surface speed can be configured tosubstantially equal the web speed of the absorbent core that is to beembossed.

As shown in FIG. 4 the rotary embossing device 30 can have an outerperipheral rim surface 32 which extends along the circumferentialdirection 42 and along the transverse cross-direction 12 of the rotaryembossing device. With reference to FIGS. 1, 4, 5 and 6, at least oneembossing member 34 can be located on the outer peripheral surface 32 ofthe rotary embossing device 30. In certain embodiments a plurality oftwo or more embossing members 34 can be distributed over the outerperipheral surface 32 in a desired array. For example, the plurality ofembossing members can be arranged in series along the circumferentialdirection of the embossing device 30, and the serial arrangement may beirregular or substantially regular, as desired.

While the embossing member 34 can be of any desired shape, design orcombination of shapes and designs for providing the desired embossmentto an absorbent article an embossing member 34 in certain embodiments,as shown in FIG. 5 may comprise a primary shape 38 bordered by two ormore secondary shapes 39.

An embossing member may provide to an absorbent article a symmetricalshape, an asymmetrical shape, a regular or irregular rectilinear shape,a regular or irregular curvilinear shape or the like, as well ascombinations thereof. The embossing member may be configured to bediscontinuous or substantially continuous, as desired. In particulararrangements, the embossing member can be arranged to effectivelyprovide a substantially closed-shape. In certain embodiments theembossing member can be configured to extend along substantially anentirety of the absorbent core perimeter during the embossing operation.

With reference to FIGS. 6 and 7, an embossing member 34 can have anembossing member height 46 and an embossing member width 48. Theembossing member height 46 is the distance between the topmost portionof the embossing member surface 47 and a corresponding localouter-surface region 32 of the embossing device. In certain embodiments,the embossing member height 46 can be from about 2 mm to about 12 mm. Incertain other embodiments the embossing member height 46 can be fromabout 3 mm to about 4 mm. With reference to FIG. 7, in certainembodiments the embossing member width 48 can be from about 0.25 mm toabout 4 mm. In certain embodiments the embossing member width 48 can befrom about 0.5 mm to about 2 mm. The embossing member 34 can includesidewall regions 64, and the sidewall regions can have a sidewall angle66. In certain embodiments the sidewall angle can be from about 0degrees to about 50 degrees. In certain other embodiments the sidewallangle can be from about 10 degrees to about 20 degrees.

As shown in FIG. 8, in certain embodiments the embossing member 34 caninclude a plurality of two or more embossing-elements 43, 44. Forexample, as shown, the embossing member 34 can include a firstembossing-element 43 and a second embossing-element 44, which is locatedadjacent the first embossing-element 43. There can be a selectedseparation distance 45 between the immediately adjacentembossing-elements 43, 44. In certain embodiments, a separation distancebetween a first 43 and second embossing-element 44 may be from about0.05 cm to about 0.8 cm. In certain other embodiments, a separationdistance between a first 43 and second embossing element 44 may be fromabout 0.1 cm to about 0.4 cm. The multi-element embossing member 34 canhave an overall width 48, as measured between an outward-edge 90 offirst embossing-element 43 and an outward edge 92 of the secondembossing-element 44. In certain embodiments the embossing member width48 can be from about 0.15 cm to about 2.2 cm. In certain otherembodiments the embossing member width 48 can be from about 0.3 cm toabout 1 cm. The first embossing-element 43 can have a first embossingelement width 48A and the second embossing-element 44 can have a secondembossing-element width 48B. In certain embodiments the first embossingelement or second embossing element width 48A, 48B can be from about0.25 mm to about 4 mm. In certain embodiments the first embossingelement or second embossing element width 48A, 48B can be from about 0.5mm to about 2 mm.

In another aspect of the method, the contacting of the topsheet 24 andabsorbent core 22 with an embossing member 34 of the rotary embossingdevice 30 can be configured to apply a selected embossing force value toan embossing region. In certain embodiments the embossing force valuecan be from about 1×10⁵ Newtons per meter (N/m) to about 3×10⁷ N/macross the width of the embossing region, for example as found in thenip region between the rotary embossing device 30 and the rotarysegmented anvil member 50. In certain embodiments the embossing forcevalue can be from about 5×10⁶ N/m to about 2×10⁷ N/m across the width ofthe embossing region, for example as found in the nip region between therotary embossing device 30 and the rotary segmented anvil member 50.

With reference to FIG. 1 the method can include attaching a backsheet 28to the topsheet 24, absorbent core 22 or both. In certain embodimentsthe backsheet 28 may be attached to the topsheet 24, absorbent core 22,or both after contacting the absorbent core 22 with the rotary embossingdevice 30. As shown in FIG. 3 portions of the backsheet 28 will conformto the contours of the depression regions 41, thereby creating anirregular surface. The various portions or components of each absorbentarticle, such as the absorbent core 22, topsheet 24 or backsheet 28 canbe joined or secured together employing any operative technique. Avariety of suitable mechanisms known to one of skill in the art may beutilized to achieve any such secured relation. Examples of such securingmechanisms or systems can include, but are not limited to, theapplication of adhesives in a variety of patterns between the twoadjoining surfaces, entangling at least some portions of one absorbentbody component with portions of the adjacent surface of anothercomponent, or fusing at least portions of the adjacent surface of onecomponent to portions of another component of the absorbent.

Referring back to FIG. 1, following its attachment a backsheet 28 iscontacted by one or more streams of adhesive, which may be in the formof meltblown adhesive, spray coating resins, or web forming resins. Asis conventionally known, the term “meltblown” is generally descriptiveof a process used to form a random network of entangled heat-fusiblefibers. In operation, a low viscosity, molten polymer is extrudedthrough a series of small discharge orifices formed in the extruder dieto define a series of continuous fibers. These fibers are immediatelyexposed to a heated, high velocity airstream for disrupting orattenuating the flow of molten polymer. Due to the flow disruptioncaused by such air impingement, the meltblown fibers are formed into arandom, entangled network of heat-fused fibers upon deposition on acontinuously moving backsheet. Thus, the resulting series of fibers aretypically continuous filaments or have one or more discrete lengths, anda fiber diameter, which in certain embodiments may be in the range offrom about 5 microns to about 120 microns, and in certain otherembodiments from about 7 microns to about 30 microns. The resultingmeltblown adhesive layer may include a plurality of such fibersdistributed in sufficient amount to achieve the desired peel force ofbetween about 70 grams of force (go to about 500 gf. The fibers may bedistributed generally in a random manner, in a non-woven manner, or in agenerally sine-wave like manner to produce an adhesive layer.

A meltblown adhesive may include one or more polymers, such as (1)cohesive strength modifiers to increase the cohesive strength, forexample aliphatic polyolefins such as ethylene-propylene copolymers,polyetheramides, polyetheresters; ethylene vinyl acetate copolymers;styrene-butadiene or styrene-isoprene block copolymers; resins oranalogous material (sometimes called a tackifier); (2) adhesive strengthmodifiers to increase the adhesive stength, for example hydrocarbonsdistilled from petroleum distillates; rosins or rosin esters; terpenesderived, for example, from wood or citrus; (3) viscosity modifiers toincrease or decrease the viscosity of a meltblown adhesive, such aswaxes, plasticizers, mineral oil, polybutene, paraffin oils, ester oils,and the like. A meltblown adhesive may also include other additivesincluding, but not limited to, antioxidants or other stabilizers.

Various plasticizing or processing oils may also be present in themeltblown adhesive compositions of the present invention in amountsranging from about 0% to about 30%, by weight of the overall adhesivecomposition, in order to aid in providing viscosity control, and furtherto operate as a diluent. Paraffinic or napthenic white processing oilsmay be used. Antioxidants or stabilizers may also be used in suitableamounts in the adhesive composition to help protect adhesives frompotentially deleterious thermal and oxidative effects, which may takeplace during the manufacture and application of adhesives. Suchdegradation, if it occurs, usually causes deterioration of the adhesivecomposition in appearance, physical properties and performance. Examplesof suitable stabilizers include one or more of high molecular weighthindered phenols and multi-functional phenols, such as sulfur andphosphorous-containing phenols.

In certain embodiments, meltblown adhesives may have a melt temperatureof between about 135° C. to about 260° C., a viscosity of less thanabout 200,000 centipoises (cps) at about 165° C., and an applicationviscosity (viscosity at about the time it is meltblown) in the range ofabout 10,000 cps to about 50,000 cps, and in certain other embodimentsin the range of about 20,000 cps to about 35,000 cps. Further, incertain embodiments, the meltblown adhesive may have a density of fromabout 0.8 g/cm³ to about 1.2 g/cm^(3.) Since the adhesive may bemeltblown, the meltblown adhesive can be capable of resulting in aforming distance (the distance between a discharge nozzle orifice and asubstrate to which the material is applied) of from about 8 mm to about25.4 mm with a resulting drop of temperature along the length of formedfilaments of about 10° C.

The adhesive may also exhibit good forming edge definition (consistencyof the adhesive pattern width during filament formation), for example anedge definition variation in certain embodiments from 0 mm to about 4mm, and in certain embodiments of from 0 mm to about 2 mm, of thedesired pattern width, when forming within a forming distance of about 8mm to about 25.4 mm. The adhesive pattern also has a defined surfacearea. The defined surface area of an adhesive pattern is the surfacearea on the substrate having at least one depression region, such as abacksheet, upon which the adhesive pattern is to be applied. In certainembodiments the adhesive covers at least 95% of the adhesive patterndefined surface area; in certain other embodiments the adhesive coversat least 90% of the adhesive pattern defined surface area; in stillfurther embodiments the adhesive covers at least 80% of the adhesivepattern defined surface area. In certain embodiments the adhesive may beapplied in an amount of from about 13 grams per square meter (gsm) toabout 19 gsm. Further less than 5% of the adhesive within the adhesivepattern defined surface area forms strings of adhesive upon removal ofthe release paper. Wherein strings of adhesive are observable by thenaked eye of the observer having 20/20 vision from a distance of about30 cm; and are formed when adhesive remains attached to both the releasepaper and substrate to which the adhesive has been applied, upon removalof the release paper—causing the adhesive to stretch and form strings.In certain embodiments, less than 2% of the adhesive within the adhesivepattern defined surface area forms strings.

FIG. 9 illustrates an example of a non-contact die means 100 that may beused in the present invention. The die means 100 comprises two diehalves, a first die half 102 and a second die half 104, and two airblocks 106, 108. Each die half 102, 104 includes a downwardly dependingprojection 110, 112. The die halves 102, 104 define between them anextrusion slot 114. The extrusion slot 114 is defined by the face 118 ofthe first die half 102 and the face 120 of the second die half 104. Face118 is juxtaposed with respect to the face 120, as shown in FIG. 9. Theextrusion slot 114 terminates at an elongated slot or extrusion outlet122.

The second die half 104 includes a hot melt passageway 124 for receivinghot melt adhesive and conducting the hot melt adhesive to a “coathanger” portion 126 of the second die half 104, which may be better seenin FIG. 10. A slotted or segmented shim 128, as best seen in FIG. 12,and a portion of which is seen in FIG. 9, is located between thejuxtaposed surfaces 118, 120 of the die halves 102, 104. The shim 128has a plurality of elongated projections 130, extending towards theextrusion outlet 122, defining between them a plurality of elongatedchannels or slots 132. In FIG. 9, only the top portion 134 of the shim128 is shown, for the purpose of clarity.

Once again with reference to FIG. 12, each of the projections 130 has adownstream tapered end portion 136, having a tip 138. In certainembodiments, an open shim can be used. An example of an open shim 140 isdepicted in FIG. 13. This shim 140 has an open area 142, with noprojections 130, as seen in FIG. 12. Also, in another embodiment, thetapered end portion 136 or tips 138 can extend beyond outlet 122.

Returning to FIG. 9, each of the die halves 102, 104 is provided with aprimary air passageway 150, 152, extending from an upper surface of thedie to a lower respective surface 154, 156. Each die half 102, 104 alsoincludes an inclined surface 158, 160, depending from the surfaces 154and 156, respectively. The inclined surfaces 158, 160 define one part ofan air elongated slot 162, 164, as will be described in more detailbelow.

Positioned below the die halves 102, 104 are the air blocks 106, 108,each of which include an inclined surface 166, 168 that defines theother side of the air slots 162, 164 with the juxtaposed respectivesurfaces 158, 160, as shown in FIG. 9. Each of the air blocks 106, 108include an upper surface 170, 172 juxtaposed to the respective lowersurfaces 154, 156 of the die halves 102, 104.

An elongated air plenum 174, 176 is formed in each of the air blocks106, 108. The plenums 174, 176 are also shown in FIG. 10. Respectivesecondary air passages 178, 180 are formed in the respective air blocks106, 108 and extend from the respective surfaces 170, 172 to a lowerportion 182, 184 of the respective plenums 174, 176. Each of the plenums174, 176 are primarily defined in the air blocks 106, 108. However, thetop areas of each of the respective plenums 174, 176 are also definedrespectively by the lower surfaces 154, 156 of the die halves 102, 104.The lower surfaces 154, 156 also form an upper portion of tertiary airpassages 186, 188, each of which respectively lead from their associatedplenums 174, 176 to the air slots 162, 164. Accordingly, as shown inFIG. 9 air can pass through the primary passageway 150 to the secondarypassageway 178 in air block 106, and from there to the plenum 174. Fromthe plenum 174, pressurized air moves through the tertiary passageway186 into the air slot 162 of the air block 106.

In a like manner, air can be introduced to primary passageway 152 in thedie half 104 and from there it can move into the secondary airpassageway 180 and into the lower portion of the plenum 176. From theplenum 176, pressurized air is directed through the tertiary air passage188 into the air slot 164 of the air block 108.

As shown in FIG. 9, in certain embodiments, a controller 175 isoperationally connected to valves V-1 and V-2, for controlling theintroduction of heated, pressurized air to the primary passages 150,152, respectively, in order to pressurize those passages and thedownstream air passages with air, as previously described. At the sametime, the controller 175 is operationally interconnected to a hot meltcontrol valve 177 for controlling the supply of coating material, suchas hot melt adhesive, to the hot melt adhesive passage 124 and to theinternal coat hanger area 126 of the die means 100. Any suitable form ofcontroller 175 can be used. A controller 175 can initiate and stop thegeneration of air into primary passages 150, 152, either simultaneouslyor independently, and can also initiate and stop the hot melt flowingthrough valve 177 so as to intermittently provide coating material tothe passageway 124, independently and at pre-selected times with respectto the supply of pressurized heated air to the primary passages 150,152, as described in more detail below.

The air slots 162, 164 are oriented on an angle with respect to thelength of the extrusion slot 114. Accordingly, when coating material isextruded through the extrusion slot 114 and outwardly of the extrusionoutlet 122, air moving through the air slots 162, 164 is impinged on thematerial before that material engages or is deposited on an underlyingsubstrate which is presented for coating.

Any suitable apparatus can be utilized for melting and pumping hot meltadhesive to the hot melt control valve 177.

Referring to FIG. 9 and the details of the die means 100 as shown inFIG. 10, it will be appreciated that the plenums 174, 176 in the airblocks 106, 108 communicate with the lower surfaces 186A, 188A,respectively, of the tertiary air passages 186, 188 as previouslydescribed, and air emanating from the upper portion of the plenums 174,176 moves through the tertiary passageways 186, 188, and then downwardlythrough the respective air slots 162, 164.

The die means 100, as shown in FIG. 10, incorporates a “coat hanger”portion 126 having an arcuate slot 190 of increasingly shallow dimensioncommunicating with an incline surface 192. Surface 192 is inclined suchthat its lower portion, where it meets bottom surface 194, is closer tothe plane of the face 120 than is the upper portion. It will also beappreciated that slot 190 is of decreasing depth as its distance fromport 195 continues until it flows unbroken in surface 192. The arcuateslot 190 of decreasing depth is fed by the hot melt port 195, which isinterconnected to the hot melt passage 124. In use, when hot meltadhesive is supplied at pressure to the passage 124, it exudes throughthe port 195 into the arcuate slot 190 and from there flows over thesurface 192 and spreads out throughout the coat hanger shaped portion126 of the die face 120 and the side of the shim 128 which is juxtaposedto the face 120 of the die half 104.

The slots 132 of the shim 128 have upper ends which communicate with thelower portion of the coat hanger die area 126, just above the surface194 thereof, so that hot melt adhesive can flow into the slots 132 andthen downwardly to the extrusion outlet 122. In this manner, the hotmelt adhesive is spread throughout the coat hanger portion 126 andacross each of the upper ends of the slots 132 of the shim 128 atsignificantly equal pressures, so that hot melt adhesive can movethrough the extrusion slot 114 within the slots 132 of the shim 128 atrelatively equal pressures.

As illustrated diagrammatically in FIG. 12, the material exudes throughthe slots 132 and then outwardly of the extrusion outlet 122.

In certain embodiments, the width of a slot 132 between the projections130 may be about twice the thickness of the shim 128. The thickness ofone shim 128 may be about 0.1 mm while the slot width—that is thedistance from one projection 130 across to the next projection 130, maybe about 0.2 mm. In another shim 128, for example, the shim thicknessmay be about 0.2 mm while the segmented slot width between juxtaposedprojections may be about 0.4 mm.

While the ratio of the shim thickness to the shim slot width may beabout 2 to 1, this ratio can be varied to produce varying hot meltadhesive thicknesses. The width and thickness parameters of the shims128, 140 and their components can vary. The parameters may vary due tothe basis weight of hot melt adhesive per square meter desired, thecohesiveness desired, the hot melt adhesive viscosity or other factors.

For the application of hot melt adhesive to an absorbent article, thedie means 100 impinges hot air from the air slots 162, 164 on each sideof the hot melt adhesive exuding from the extrusion outlet 122. Theimpinging air engages and shreds the hot melt adhesive into discretemicro-denier fibers. Edge control is uniform and the density of thepattern can range from 25% open or fibrous to 0% open, for example anon-porous film. The parameters are selected depending on theapplication to which the hot melt adhesives are to be applied.

In certain embodiments the die means 100 can selectively apply air flowthrough either air slot 162 or 164 individually or together during thedeposition period, particularly to more accurately define the initialand ending contact position of the deposited coating on the substrate.One such mode of operation is illustrated in FIG. 11, where theapparatus is utilized, for example, to apply a hot melt adhesive to thebacksheet of feminine sanitary napkin so that a release paper can beoperatively attached thereto.

In FIG. 11, a feminine sanitary napkin with no adhesive thereon is shownat the left hand side of the figure at position B-1. As illustrated atB-1, air flow has been initiated through the air slots 162, 164 butthere is no hot melt adhesive being extruded through the extrusion slot114. Moving to the feminine sanitary napkin at the position B-2, it willbe appreciated that the hot melt flow adhesive has started and that itis impinged by air flowing through the air slots 162, 164. Since the airflowing through the air slots 162, 164 at position B3 and B4 movesdownwardly in a general right to left direction as shown in FIG. 11, itwill be appreciated that the hot melt adhesive does not string down theside of the feminine sanitary napkin but is applied directly to thebacksheet of the feminine sanitary napkin with no stringing. Then, asshown in position B-5, the hot melt adhesive flow has ceased, while theair flowing through the air slots 162, 164 continues. This operation,when used in operatively attaching release paper to the backsheet of afeminine sanitary napkin, for example, would ensure that the adhesivewill not string down the edges of the feminine sanitary napkin.

Accordingly, with respect to FIG. 11, the air flow is started before theextrusion of the hot melt adhesive and stopped after the hot meltadhesive extrusion has ceased. In this way, the air angling onto the hotmelt adhesive does not blow it in strings over the edges of the femininesanitary napkin, as that would be undesirable and yet the cut-off andcut-on edges of the hot melt adhesive are maintained in sharp, squarefashion on the backsheet of the feminine sanitary napkin.

In FIGS. 14-16, a feminine sanitary napkin 80 is illustrated, such thatthe garment facing surface 27 is visible and the backsheet 28 anddepression region 41 can be seen. An adhesive pattern 81 having adefined surface area that may be comprised of lines or bands of adhesiveis applied by the apparatus described herein, in either fibrous orimpervious form, to the backsheet 28 to releasably operatively attachthe release paper 82. There can be more than one adhesive pattern perindividual backsheet, for example an individual backsheet may have 2, 3,4 or more individual adhesive patterns. Further the adhesive patternsmay be in any suitable shape, for example rectangles, squares,crisscross patterns, asymmetric or symmetric shapes, and so on. As shownin FIG. 16 the adhesive pattern 81 present in both the substantiallyflat portions of the backsheet 28 and the portions of the backsheet 28that conform to the depression region 41. The non-contact application ofthe adhesive allows the adhesive to adhere to the substantially flatportions of the backsheet 28 and the depression regions 41 providingincreased adhesive coverage within the defined surface area of theadhesive pattern 81; as compared to contact methods of adhesiveapplication, as described below. FIGS. 14-16 illustrate the adhesivepatterns 81 may vary in width. The adhesive patterns can be applied asdisclosed herein oriented along a feminine sanitary napkin manufacturingline at predetermined positions as necessary, with sharp and squareside, leading and trailing edges.

FIGS. 17 and 18 are cross-sections of feminine sanitary napkins in thesame position as shown in FIGS. 15 and 16; and illustrate adhesiveapplications that do not provide the benefits of the present invention.When a contact method of adhesive application, such as using a slot coatapplicator, roller or brush, is used to apply adhesive 180 to abacksheet 182 of a feminine sanitary napkin 184, as shown in FIG. 16,the adhesive is not applied to the recessed areas of a depression region186. This inadequate transfer of adhesive from the release paper to thebacksheet increases the likelihood of stringing and residue, potentiallytransferring adhesive to unintended surfaces, such as a user's pantiesor hands.

When adhesive is first applied to release paper using a slot coatapplicator, roller or brush, and then the release paper is operativelyattached to a backsheet, as shown in FIG. 18, the adhesive 190 presenton the release paper 192 does not come into direct contact with therecessed portion of a depression region 194. The adhesive 190 present onthe release paper 192 forms strings 196 of adhesive 190 in the gapbetween the release paper 192 and the depression region 194 present inthe backsheet 198 of the feminine sanitary napkin 200. During use, whenthe release paper 192 is separated from the backsheet 198 the strings196 remain attached to both the release paper 192 and the depressionregion 194. The dual attachment causes the strings 196 of adhesive tostretch. The stretched strings of adhesive can then attach to unintendedsurfaces they contact complicating placement of the feminine sanitarynapkin and increasing clean-up.

EXAMPLES

Release paper was examined to determine if adhesive remained attached tothe release paper following its removal from a feminine sanitary napkin.

Example 1

Sample Preparation

Sample testing was done at room temperature and at standard pressure andhumidity.

Samples were prepared by the method described herein. Specifically thesamples were ALWAYS® Maxi Pads that were embossed prior to having apolypropylene backsheet attached. An ALWAYS® Maxi Pad was embossed withthe embossment region shown in FIG. 19 so that the body facing surface(topsheet) had an average side embossment depth of 5.5 mm and an averageend depth of 2.7. The garment facing surface (backsheet) of an ALWAYS®Maxi Pad had an average side depression region depth of 2.6 mm and anaverage end depression depth of 2.8 mm.

For contact application of adhesive to release paper—Adhesive—EASYMELT®34-689B from National Starch & Chemical Co., Bridgewater, N.J.; in anamount of 15 grams per square meter (gsm), was applied using an EP 11Slot Applicator, Nordson Corp., Westlake, Ohio to release paper at atemperature of between 155° C. and 160° C. in two 18 mm wide rectangularshaped patterns spaced 13 mm apart, and having a length (as measured inthe MD) that is 7 mm shorter in both the front and rear ends than theapplied release paper Immediately after adhesive application the releasepaper was attached to a feminine sanitary napkin. The release paper usedwas silicone based release paper RP MONDI 35 gsm 54 mm (width) unprinted(Mondi plc, Addleston Surrey, UK) was cut to length using a cut and slipanvil. The release paper length extended 7 mm past the front end of theadhesive pattern and 7 mm past the rear end of the adhesive pattern asmeasured in the MD. Following attachment of the release paper, theadhesive was allowed to set for one hour before the release paper wasremoved.

For non-contact application of adhesive to abacksheet—Adhesive—EASYMELT® 34-689B from National Starch & ChemicalCo., Bridgewater, N.J.; in an amount of 15 gsm, was applied using aControl Coat Applicator, Nordson Corp., Westlake, Ohio, to the backsheetof a feminine sanitary napkin at a temperature of between 155° C. and160° C. in two 18 mm wide rectangular shaped patterns spaced 13 mmapart, and having a length (as measured in the MD) that is 7 mm shorterin both the front and rear ends than the applied release paperImmediately after adhesive application the release paper was attached toa feminine sanitary napkin. The release paper used was silicone basedrelease paper RP MONDI 35 gsm 54 mm (width) unprinted (Mondi plc,Addleston Surrey, UK) was cut to length using a cut and slip anvil. Therelease paper length extended 7 mm past the front end of the adhesivepattern and 7 mm past the rear end of the adhesive pattern as measuredin the MD. Following application, the adhesive was allowed to set forone hour before the release paper was removed.

Sample Testing

For removal of the release paper a sample ALWAYS® Maxi Pad was held inone hand and the release paper was held in the other hand. The releasepaper was then removed at a speed a normal user would use. The directionin which the release paper was peeled from the ALWAYS® Maxi Pad did notaffect the results. The release paper was then observed for the presenceof adhesive.

As shown in FIG. 20, samples were considered to have failed the test ifthe following was observed after removal of the release paper: adhesiveresidue in the form of three or more adhesive globules or strings on therelease paper having an average diameter of 4 mm or greater followingthe release paper's removal. Stringing includes adhesive that staysattached to both the backsheet and release paper following removal ofthe release paper and forms adhesive strings between backsheet andrelease paper.

TABLE 1 Contact Non-Contact Application of Application of AdhesiveSamples Adhesive Samples Number of Samples Tested 200 200 Presence ofthree or more 200   0 adhesive globules or strings

The results show that samples in which the adhesive had been applied tothe release paper using a slot applicator (contact method) all of the200 samples tested had enough adhesive present on the release paper tofail the test. Adhesive present on the release paper results in usersnot liking the product, as the residual adhesive (either in the form ofa string, globule, or both) can get on the user's hands clothes or theabsorbent article, in this example a feminine sanitary napkin,interfering with the placement of the feminine sanitary napkin. Incontrast all of the samples produced using a non-contact method ofadhesive application to the backsheet, as in the present invention,passed the test, in that none of the samples were observed to have threeor more adhesive globules or strings present on the release paper. Thisdemonstrates that the adhesive applied using the present invention isapplied to and remains in the embossed regions of the samples after theremoval of the release paper; in contrast to the adhesive applied usinga contact method which is partially removed from the feminine sanitarynapkin when the release paper is peeled away.

Example 2

The samples were tested to determine the peel force of adhered cotton topressure sensitive adhesive. A sample having proper peel force helpsensure the product will stay in place during consumer use, but can beremoved without too much difficulty.

Equipment

-   -   Cotton Swatch White, 100% die-cut 76 mm×457 mm cotton weave        (Style #429-W); available from Testfabrics, Inc., West Pittston,        Pa.    -   Friction Grip Frame Plexiglas plate 80 mm wide by 250 mm long by        2 mm thick, having an open rectangular window 67 mm wide by 175        mm long.    -   Rigid peel plate smooth steel plate 75 mm wide by 230 mm long by        1.5 mm thick having a raised center portion (about 1 mm as        measured from the plate surface) that was slightly smaller than        the open rectangular window in the friction grip frame (about 1        mm in each direction) to accommodate, yet grip, the sample.    -   Compression Weight . . . Metal weight 60 mm wide by 220 mm long,        having an area of 132 cm² to provide a mass of 3.50 kg+/−0.07        kgm, so as to cover the adhesive area being tested and apply        26-27 g/sqcm to the sample.        -   Compressible Polyurethane foam, 25 mm thick, cut to fit the            weight length and width dimensions. The hardness of the foam            should be between 20 and 80 using a Shore Hardness sponge            rubber gauge such as the PTC 302SL from PTC Instruments, LA,            Calif. Foam can be ordered from Concord-Renn Company,            Cincinnati, Ohio.        -   Plexiglas plate, fitting the weight length and width            dimensions, and having a thickness of 6.4 mm        -   Transparent Tape (19 mm wide), such as Scotch® Magic™ Tape,            from 3M, St. Paul, Minn.        -   Polyethylene film, 0.02-0.04 mm thick, having length and            width dimensions large enough to enclose the polyurethane            foam and Plexiglas plate.    -   Assembly of the compression weight: (See FIG. 21)        -   1. Polyethylene film was laid on a flat surface.        -   2. Urethane Foam was positioned on top of the polyethylene            film so that the long sides of the foam are parallel with            the long sides of the polyethylene film        -   3. Plexiglas plate was placed on top of the urethane foam.        -   4. Polyethylene film was folded up over the urethane foam            and secured to the Plexiglas plate using transparent tape.        -   5. The four corners of the urethane foam/Plexiglas plate            were aligned with the four corners of the compression            weight; with urethane foam side positioned away from the            metal surface.        -   6. Urethane foam/Plexiglas plate was secured to the            compression weight using transparent tape.    -   Tensile Tester . . . MTS Alliance RT-1 Frame; with load cell        capacity of 10-100 Newtons (N), available from MTS Systems        Corporation, Eden Prairie, Minn.

Tensile Tester Settings

Set the tensile tester to the following values:

Test Speed* 1016 mm/min Grip to Grip separation 250 mm Pre loading 0Pre-test path “LB” 58 mm Test path “LM” 170 mm Break Detector 0 MeasureVariable F_(avg) in “LM” Sampling Frequency 50 Hz

Sample Preparation

Sample testing is done at room temperature and at standard pressure andhumidity.

Samples were prepared by the method described herein. Specifically thesamples were ALWAYS® Maxi Pads that were embossed prior to having apolypropylene backsheet attached. An ALWAYS® Maxi Pad was embossed withthe embossment region shown in FIG. 19 so that the body facing surface(topsheet) had an average side embossment depth of 5.5 mm and an averageend depth of 2.7. The garment facing surface (backsheet) of an ALWAYS®Maxi Pad had an average side depression region depth of 2.6 mm and anaverage end depression depth of 2.8 mm.

For contact application of adhesive to release paper—Adhesive—EASYMELT®34-689B from National Starch & Chemical Co., Bridgewater, N.J.; in anamount of 15 gsm, was applied using an EP 11 Slot Applicator, NordsonCorp., Westlake, Ohio to release paper at a temperature of between 155°C. and 160° C. in two 18 mm wide rectangular shaped patterns spaced 13mm apart, and having a length (as measured in the MD) that is 7 mmshorter in both the front and rear ends than the applied release paper.Immediately after adhesive application the release paper was attached toa feminine sanitary napkin. The release paper used was silicone basedrelease paper RP MONDI 35 gsm 54 mm (width) unprinted (Mondi plc,Addleston Surrey, UK) was cut to length using a cut and slip anvil. Therelease paper length extended 7 mm past the front end of the adhesivepattern and 7 mm past the rear end of the adhesive pattern as measuredin the MD. Following attachment of the release paper, the adhesive wasallowed to set for one hour before the release paper was removed.

For non-contact application of adhesive to abacksheet—Adhesive—EASYMELT® 34-689B from National Starch & ChemicalCo., Bridgewater, N.J.; in an amount of 15 gsm, was applied using aControl Coat Applicator, Nordson Corp., Westlake, Ohio, to the backsheetof a feminine sanitary napkin at a temperature of between 155° C. and160° C. in two 18 mm wide rectangular shaped patterns spaced 13 mmapart, and having a length (as measured in the MD) that is 7 mm shorterin both the front and rear ends than the applied release paper.Immediately after adhesive application the release paper was attached toa feminine sanitary napkin. The release paper used was silicone basedrelease paper RP MONDI 35 gsm 54mm (width) unprinted (Mondi plc,Addleston Surrey, UK) was cut to length using a cut and slip anvil. Therelease paper length extended 7 mm past the front end of the adhesivepattern and 7 mm past the rear end of the adhesive pattern as measuredin the MD. Following application, the adhesive was allowed to set forone hour before the release paper was removed.

Sample Preparation (Shown in FIGS. 22 and 23)

-   -   1. A sample was placed with the adhesive side up; onto the rigid        peel plate (FIG. 22).    -   2. The sample was secured on the rigid peel plate by placing the        friction grip frame over the sample (FIG. 22).    -   3. The release paper was then peeled from the adhesive (FIG.        22).    -   4. Within five minutes following removal of the release paper a        cotton swatch was laid over the exposed adhesive. One end of the        cotton swatch extended past the top or bottom edge of the        adhesive by about 25 mm (cotton swatch leading end); (FIG. 23).    -   5. The compression weight was then placed on the cotton swatch        so that the compression weight completely covered the adhesive        area (FIG. 23). Force was not used to apply the compression        weight to the cotton swatch, rather the compression weight was        placed on the cotton swatch without any pressure being applied        by the tester's hand; as deviations in how the compression        weight is placed from sample to sample can cause variations in        results, for example dropping the compression weight down onto        the sample results in much higher compression forces, and higher        resulting peel force. The compression weight was left on the        sample for 30 seconds (±2 s).    -   6. The weight was gently removed without adding any extra        pressure to the sample while lifting the compression weight        (FIG. 23).

Sample Testing

Samples were tested within b 1 minute after the compression weight wasremoved.

-   -   1. The load cell was tared (zeroed)    -   2. The top end of the rigid peel plate was placed into the lower        clamp of the tensile tester and the tail end of the cotton        swatch was placed into the upper clamp with the load cell.    -   3. The rigid peel plate and the cotton swatch were adjusted in        the upper and lower clamps, so that the cotton swatch is lined        up with the top or bottom edge of the adhesive pattern (peel        line), as shown in step 6 of FIG. 23.    -   4. The cotton swatch was checked to ensure it was not loose        before fixing it into the upper clamp and the peel line is        evenly centered and parallel to the upper and lower clamps.        There was 0.1 N of tension on the cotton swatch at the start of        the test. This initial tension was not tared (zeroed).    -   5. The tensile tester was started and the upper clamp (see step        in FIG. 23) began to pull the cotton swatch (Pre-test path        “LB”). At 58 mm into the pull data collection was started and        ended at 170 mm (Test path “LM”). The data collected between the        58 mm mark and the 170 mm mark was averaged for each pad tested,        and is shown in TABLES 2 and 3.

TABLE 2 Contact Application of Adhesive Samples Avg Load in Peak Load ingrams of force grams of Sample (gf) force (gf) 1 223.1 462.7 2 260.8590.5 3 247.7 568.  4 306.1 889.1 5 353   925.3 Avg 278.1 687.1 Std 51.5 206.9 Deviation

TABLE 3 Non-Contact Application of Adhesive Samples Avg Load Peak Load(gf) (gf)  6 294.3 573    7 305.8 520.3  8 274.3 514.2  9 306.5 541.9 10352.7 574.4 Avg 306.7 544.7 Std  28.8  28.3 Deviation

The results in TABLE 2 and TABLE 3 show that the peel force (amount offorce used to remove the cotton swatch from the adhesive) is moreconsistent when adhesive is applied using a non-contact method ascompared to a contact method of adhesive application. The consistency ofthe peel force is dramatically better for samples prepared using anon-contact adhesive application (samples 6-10) as compared to samplesprepared using a contact adhesive application (samples1-5)-for samples6-10 the standard deviation for Average Load in Grams of Force was 28.8gf and the standard deviation for Peak Load in Grams of Force was 28.3gf; as compared to samples 1-5 that had a standard deviation for AverageLoad in Grams of Force of 51.5 gf and a standard deviation for Peak Loadin Grams of Force of 206.9 gf. Consistency of peel force is an importantelement of adhesion performance for an adhesive. If the peel force istoo low, then the ability of the absorbent article, in this example afeminine sanitary napkin, to stay in place (attached to the cottonswatch) is compromised; if the peel force is too high, it is difficultto remove the feminine sanitary napkin from the cotton swatch. Reducingthe variability in peel force significantly reduces the probability ofhaving feminine sanitary napkins at either problematic extreme. And thereduction in peel force variability is illustrated in the comparativelylow standards of deviation (28.8 gf and 28.3 gf) observed in samples6-10 as compared to the comparatively high standards of deviation (51.5gf and 206.9 gf) observed in samples 1-5.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A method for embossing an absorbent article comprising the steps of:providing a topsheet; providing an absorbent core having a garmentfacing side and a body facing side and positioning the body facing sideof the absorbent core on the topsheet; moving the topsheet and absorbentcore in a machine direction; operatively contacting the garment facingside of the absorbent core with a segmented anvil member and thetopsheet with an embossing member of a rotary embossing device to forman embossment region in at least a portion of the topsheet and bodyfacing side of the absorbent core and a depression region in the garmentfacing side of the absorbent core; contacting a backsheet with thegarment facing side of the absorbent core having a depression region;applying adhesive in a pattern to the backsheet using a non-contact diemeans; and operatively attaching a release paper to the backsheet. 2.The method of claim 1, wherein the segmented anvil member comprises twoor more segmented sections and each segmented section includes two ormore movable portions such that the movable portions reduce the distancebetween an embossment member and the segmented anvil member.
 3. Themethod of claim 1, wherein the embossing member has a height that isfrom about 2 mm to about 12 mm.
 4. The method of claim 1, wherein theembossing member applies a force value of about 1×10⁵ N/m to about 3×10⁷N/m to the embossment region.
 5. The method of claim 1, wherein theembossing member forms an embossment region having a depth of about 20%to about 75% of the thickness of the absorbent article.
 6. The method ofclaim 1, wherein the embossing member forms a depression region having adepth of about 15% to about 75% of the thickness of the absorbentarticle.
 7. The method of claim 1, wherein the adhesive is a meltblownadhesive.
 8. The method of claim 1, wherein the adhesive pattern has adefined surface area, the adhesive covering at least about 80% of thedefined surface area.
 9. The method of claim 1, wherein the adhesivepattern has a width and defined surface area, the adhesive covering atleast about 90% of the defined surface area.
 10. The method of claim 9,wherein the adhesive pattern has an edge definition variation within 0mm to about 2 mm of the pattern width, when forming within a formingdistance of about 8 mm to about 25 mm.
 11. A method for embossing anabsorbent article comprising the steps of: providing a topsheet;providing an absorbent core having a garment facing side and a bodyfacing side and positioning the body facing side of the absorbent coreon the topsheet; moving the topsheet and absorbent core in a machinedirection; operatively contacting the garment facing side of theabsorbent core with a segmented anvil member and the topsheet with anembossment member of a rotary embossing device to form an embossmentregion in at least a portion of the topsheet and body facing side of theabsorbent core and a depression region in the garment facing side of theabsorbent core; contacting a backsheet with the garment facing side ofthe absorbent core having a depression region; applying adhesive in apattern to the backsheet using a non-contact die means; wherein theapplication of adhesive comprises the steps of: extruding adhesive froman extrusion outlet; impinging a flow of air from the extrusion outletat an angle unto the extruding adhesive; depositing extruded adhesiveonto the backsheet; and operatively attaching a release paper to thebacksheet.
 12. The method of claim 11, wherein the segmented anvilmember comprises two or more segmented sections and each segmentedsection includes two or more movable portions such that the movableportions reduce the distance between an embossment member and thesegmented anvil member.
 13. The method of claim 11, wherein theapplication of adhesive also comprises the step of starting and stoppingthe extrusion of adhesive to produce discrete adhesive patterns.
 14. Themethod of claim 11, wherein the embossing member has a height that isfrom about 2 mm to about 12 mm.
 15. The method of claim 11, wherein theembossing member applies a force value of about 1×10⁵ N/m to about 3×10⁷N/m to the embossment region.
 16. The method of claim 11, wherein theembossing member forms a depression region having a depth of about 15%to about 75% of the thickness of the absorbent article.
 17. The methodof claim 11, wherein the adhesive is a meltblown adhesive.
 18. Themethod of claim 11, wherein the adhesive pattern has a defined surfacearea, the adhesive covering at least about 80% of the defined surfacearea.
 19. The method of claim 11, wherein the adhesive pattern has awidth and defined surface area, the adhesive covering at least about 90%of the defined surface area.
 20. The method of claim 19, wherein theadhesive pattern has an edge definition variation within 0 mm to about 2mm of the pattern width, when forming within a forming distance of about8 mm to about 25 mm.